Sewing needle particularly adapted for sewing with threads of synthetic fibers



Oct. 1, 1968 P. SUPITAR 3,403,647

SEWING NEEDLE PARTICULARLY ADAPTED F SEWING WITH THREADS OF THETIC FIB Filed 7, 1966 INVENTORI Pefr SUPITAR his Affornej United States PatentlO ABSTRACT OF THE DISCLOSURE A sewing needle of novel configuration and shape, having an eye portion which has an overall cross-sectional dimension that exceeds the nominal diameter of the needle by at least 0.08 mm., while the portion of the needle above the needle eye is thinner than the nominal diameter of the needle.

The present invention generally relates to sewing needles and in particular to a novel construction for a sewing needle.

Due to the rapid reciprocal stroke movement of sewing needles during the sewing operation, these needles often become very hot due to friction. Elevated temperatures have an adverse effect on threads made from synthetic fibers and on textile material made from synthetic fibers. Heretofore, not very much attention was given to the shape of the needles used in the sewing operation because threads made from natural fibers or material composed of natural fibers are not very sensitive to heat and, consequently, rapid sewing can be carried out with the sewing needles of known shape and construction without affecting the material and threads made from natural fibers. When synthetic fibers are used, however, certain problems arise in a rapid sewing operation. Thus, for example, the sewing needles become covered with molten parts of synthetic fiber threads; the synthetic fiber threads often tear; poorly sewed seams are produced; and other similar problems arise. Consequently, the output of the sewing machine is reduced and the quality of the sewed material is also lowered. In order to eliminate these disadvantages cooling arrangements for the sewing needle have been incorporated in sewing machines of the prior art. It is also known to cool the sewing needle by air or liquid during the sewing operation. Lastly, it is also known to give the sewing needle a special shape which favors the cooling thereof during rapid sewing.

None of the aforedescribed arrangements of the prior art have proven to be fully satisfactory.

It is therefore a general object of the present invention to provide a sewing needle of such configuration and shape that the temperature of the sewing needle during the sewing operation does not rise above a safe level.

It is another object of the present invention to provide a sewing needle of increased stifiness which prevents excessive vibration during the sewing operation.

It is still another object of the present invention to provide a sewing needle in which the location of the region which acts on the synthetic fiber thread is displaced when compared with the known sewing needles.

It has been found that a sewing needle having the shape, configuration and construction in accordance with this invention renders excellent results during rapid sewing of synthetic fiber material. Furthermore, a sewing machine operating with a needle of this invention can increase its output without lowering the quality of the seams when compared to the seams produced with ordinary sewing needles.

, 3,403,647. Patented Oct- 1 1968 The sewing needle of this invention is, characterized by the outline of the needle in theneedle eye portion having an overall cross-sectional dimension that exceedsthe nominal diameter. of the needle by atleast 0.08 mm., while the portion of the needle above the needle eye .is thinner than the nominal diameter of the needle.

Theinvention will be further described, by way of example, with reference to the accompanying drawing, in

which:

FIG. 1 is an elevation of the sewing needle of this invention; p

FIG. 2 is a cross-section along line A--A of FIG. 1; and

FIG. 3 is a cross-section along line BB of FIG. 1.

Referring now to the drawing there is illustrated in FIG. 1 the sewing needle of this invention'in which the portion 3 of the needle eye is thicker than the nominal diameter at the first blade portion .1 of the needle, whereas the second blade portion 2 of the needle above I the needle eye portion is thinner than the nominal diameter of the portion 1 of the needle. The excess thickness of the portion 3 in excess of the nominal diameter of the portion 1 is symmetrically disposed about the axis of the needle and amounts to at least 0.08 mm. The thickness of the region of the needle eye in prior art sewing needles has also been occasionally increased due to the stamping of the needle eye into the needle body. However, the increase in thickness in the needle due to stamping lies within the finishing tolerances of this type of product and is, therefore, of an entirely different dimensional order which is significantly below the specified minimum of 0.08 mm. in the sewing needle of this invention. As a consequence of the special shape of the needle of this invention, a considerable reduction of the needle friction during traversal of the material is effected which results in a reduced temperature increase in the needle during rapid sewing.

The needle of this invention is further provided with longitudinal grooves 4 extending along both sides from the needle eye upwardly which facilitate a drawing off of the heat energy and also shift the region of maximum temperature in the needle toward the needle point portion.

Furthermore, the needle of this invention is also provided with a hole 6 located between the needle eye and the needle point portion, which also aids in shifting the maximum temperature center away from the needle eye.

The needle of this invention is further provided with a longer than normal cone portion 5 which connects the shank 7 of the needle to the portion 1 having the nominal diameter. This longer than normal cone portion 5 effects an increased stiffness of the needle when compared with the normal sewing needles. Thus, needles with such an elongated cone portion 5 have increased stability and considerably reduced vibrations during rapid sewing. Furthermore, the elongated cone portion 5 also facilitates the drawing olf of heat energy located between the needle eye portion and the shank 7.

Furthermore, the needle shank 7 proper is also longer than ordinary needle shanks, 'which increases to overall stiffness of the needle and its ability to draw off heat energy from the cone portion.

The sewing needle of this invention may be used with all types of sewing machines without requiring any ad justing or fitting in the sewing machine. When an accessory cooling unit is used in the sewing machine the results obtained with the sewing needle of this invention are even better.

Although the present invention has been described in conjunction with one preferred embodiment, it is to be understood that modifications and variations may be resorted to without departing from the spirit and scope of the invention, as those skilled in the art 'will readily unered to bewi'thiri the purviewa'nd scope'of the invention and appended claims.

What I claim is:

1. An improved sewing needle of the character described, having a shank portion at one end thereof and apointed end portion at the other end thereof, a blade portion, and a needle-eye portion adjacent "to said pointed end portion, the cross-section of a first portion of said blade portion of said needle, which is located between the shank and needle eye portions defining a nominal diameter of said needle, said needle having a needle eye within said needle eye portion, the diameter of the crosssection of said needle eye portion exceeding said nominal diameter byat least 0.08 mm.

2. The improved sewing needle as set forth in claim 1, wherein the average diameter of the cross-section of a second portion of said blade portion between said needle eye portion and said first portion of said blade portion having the cross-section which define the nominal diameter thereof is smaller than said nominal diameter.

3. The improved sewing needle as set forth in claim 2,

including at least one groove longitudinally extending along the axis of said needle within said needle-eye portion, thereby reducing the cross-sectional area of said needle-eye portion.

4. The improved needle as set forth in claim 2, wherein said needle has-an opening located between the needle eye and the pointed. end portion of said needle.

5. The improved needle as set forth in claim 2, wherein said needle has a conically shaped portion between said first blade portion having the cross-section which defines the nominal diameter thereof and said shank porti'on.

6. The improved needle as set forth in claim 5, 'wherein said conically shaped portion has an apex angle of less than 10. V i Y References Cited UNITED STATES PATENTS 568,946 10/ 1896 Hanna 1l2--222 FOREIGN PATENTS 146,829 6/ 1952 Australia.

RICHARD J. SCANLAN, JR., Primary Examiner. 

